The invention belongs to the technical field of building deformation measurement and particularly relates to a high tower tube bending degree detection method based on three-dimensional laser scanning. The method comprises the steps of (1) arranging an instrument through retention points which are symmetrically arranged around a tower tube as a center, and obtaining point cloud data of a tower tube body, (2) constructing a tube body TIN model, selecting tower tube cross sections, and carrying out fitting of a tower tube central axis, (3) randomly selecting n points or selecting n points with a set interval along a counter-clockwise (or clockwise) direction at the edge perimeters of the cross sections and carrying out reduction of barycentric coordinates of the tower tube cross sections, and (4) calculating a tower tube bending displacement component, a bending displacement resultant and a bending average curvature according to an adjacent cross section through the obtained barycentric coordinates of the tower tube cross sections. According to the method, the disadvantages of difficult field operations, difficult precision control, time and labor consumption, poor accuracy of target data and a large data limitation in the traditional detection of a high tower tube bending degree are solved, the high tower tube bending degree detection can be rapidly and precisely realized, and the method has important practical significance for similar engineering detection and monitoring.